1. Field of the Invention
The present invention relates to a temperature detector for measuring the temperature of a heat exchanger of a vehicular air-conditioning unit.
2. Description of the Related Art
Vehicular air-conditioning units include an evaporator (cooling heat exchanger) for cooling outside air delivered from a blower unit. The outside air is cooled by a heat exchange with a coolant which flows in the evaporator. After the outside air is cooled, part of the cooled outside air is brought into contact with a heater and heated thereby. The heated outside air is then mixed with the remaining cooled outside air which has passed through a bypass passage without contacting the heater. The mixed air is then introduced as conditioned air at a desired temperature from air outlets into the passenger compartment of the vehicle.
The rate at which the cooled outside air is supplied to the heater or bypass passage is adjusted by the opening of a door member of a damper mechanism which is disposed near the evaporator.
A temperature detector has a temperature detecting tip end held against the evaporator at a given position (see, for example, Japanese Laid-Open Patent Publication No. 2006-017406 and Japanese Laid-Open Patent Publication No. 2006-232257). The temperature detector detects the temperature of the evaporator, and a temperature control mechanism, not shown, controls the temperature of the coolant which flows in the evaporator to stay within a predetermined range based on the detected temperature.
The temperature detector is retained on the evaporator by a holder. The holder has an insertion protrusion which is inserted in and engaged by fins of the evaporator, thereby holding the holder on the evaporator.
As shown in FIG. 14 of Japanese Laid-Open Patent Publication No. 2006-017406 and FIG. 7 of Japanese Laid-Open Patent Publication No. 2006-232257, a harness (leads) is connected to an end of the temperature detector. As described above, the evaporator is supplied with outside air from the blower unit. Therefore, if the harness is loose, then the harness tends to vibrate under the pressure of the outside air which is applied to the harness. The harness is liable to vibrate more as the length of the harness connected to the temperature detector is larger as shown in FIG. 14 of Japanese Laid-Open Patent Publication No. 2006-017406.
When the largely-vibrating harness hits the evaporator and the damper mechanism, it produces noise. If the harness is entangled with the damper mechanism, then the door member of the damper mechanism may possibly be prevented from achieving a desired opening or may possibly cut off the harness when the door member is opened and closed.
One solution would be to reduce the length of the harness connected to the temperature detector for reducing the vibration of the harness. However, the shorter harness would make the temperature detector unable to measure the temperature of a central region of the evaporator.